package com.ruoyi.common.utils.ip;

import javax.servlet.http.HttpServletRequest;

public class ClientIPUtils {

    public static String getClientIP(HttpServletRequest request) {
        String ip = request.getHeader("X-Forwarded-For");
        if (ip == null || ip.isEmpty() || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (ip == null || ip.isEmpty() || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.isEmpty() || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (ip == null || ip.isEmpty() || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED");
        }
        if (ip == null || ip.isEmpty() || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_CLUSTER_CLIENT_IP");
        }
        if (ip == null || ip.isEmpty() || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_CLIENT_IP");
        }
        if (ip == null || ip.isEmpty() || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_FORWARDED_FOR");
        }
        if (ip == null || ip.isEmpty() || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_FORWARDED");
        }
        if (ip == null || ip.isEmpty() || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        
        // 对于通过多个代理的情况，第一个IP为客户端真实IP
        if (ip != null && !ip.isEmpty()) {
            int idx = ip.indexOf(',');
            if (idx > 0) {
                ip = ip.substring(0, idx);
            }
        }
        
        return ip;
    }
}
